Unified deep learning model for predicting fundus fluorescein angiography image from fundus structure image

The prediction of fundus fluorescein angiography(FFA)images from fundus structural images is a cutting-edge research topic in ophthalmological image processing.Prediction comprises estimating FFA from fundus camera imaging,single-phase FFA from scanning laser ophthalmoscopy(SLO),and three-phase FFA also from SLO.Although many deep learning models are available,a single model can only perform one or two of these prediction tasks.To accomplish three prediction tasks using a unified method,we propose a unified deep learning model for predicting FFA images from fundus structure images using a supervised generative adversarial network.The three prediction tasks are processed as follows:data preparation,network training under FFA supervision,and FFA image prediction from fundus structure images on a test set.By comparing the FFA images predicted by our model,pix2pix,and CycleGAN,we demonstrate the remarkable progress achieved by our proposal.The high performance of our model is validated in terms of the peak signal-to-noise ratio,structural similarity index,and mean squared error.

Fundus autofluorescence in central serous chorioretinopathy: association with spectral-domain optical coherence tomography and fluorescein angiography

and FA for identifying pathological abnormalities in CSC. The characteristics of IA AF in CSC were attributable to the modification of melanin in the RPE. IR- AIM: To evaluate the correlation among changes in fundus autofluorescence (AF) measured using infrared fundus AF (IR -AF) and short-wave length fundus AF (SW -AF) with changes in spectral -domain optical coherence tomography (SD -OCT) and fluorescein angiography (FA) in central serous chorioretinopathy (CSC). METHODS: Two hundred and twenty consecutive patients with CSC were included. In addition to AF, patients were assessed by means of SD -OCT and FA. Abnormalities in images of IA -AF, SW -AF, FA were analyzed and correlated with the corresponding outer retinal alterations in SD-OCT findings. RESULTS: Eyes with abnormalities on either IR-AF or SW-AF were found in 256 eyes (58.18%), among them 256 eyes (100%) showed abnormal IR -AF, but SW-AF abnormalities were present only in 213 eyes (83.20%). The hypo-IR-AF corresponded to accumulation of subretinal liquid, collapse of retinal pigment epithelium (APE) or detachment of APE with or without RPE leakage point in the corresponding area. The hyper -IR -AF corresponded to the area with loss of the ellipsoid portion of the inner segments and sub -sensory retinal deposits or focal melanogenesis under sensory retina. The hypo-SW-AF corresponded to accumulation of subretinal liquid or atrophy of RPE. The hyper -SW -AF associated with sub -sensory retinal deposits, detachment of RPE and focal melanogenesis. CONCLUSION: IR-AF was more sensitive than SW-AF AF should be used as a common diagnostic tool for identifying pathological lesion in CSC.

Fractal analysis of retinal vasculature in normal subjects on ultra-wide field fluorescein angiography

AIM: To evaluate the fractal feature of the retinal vasculature of normal eyes on a stereographic projected and montaged ultra-wide field(UWF) fluorescein angiography(FA).METHODS: Prospective, observational, cross-sectional study. Totally 59 eyes of 31 normal subjects were imaged using the Optos 200 Tx. Images obtained at different gaze angles stereographically projected and montaged. The early-phase UWF FA frames were processed to segment the retinal vasculature and the results were exported as binary masks. The fractal dimension(FD) was calculated using the box-counting method.RESULTS: The global FD for the entire retina was 1.6±0.04, with no difference between males and females(1.59±0.04 vs 1.61±0.04, P=0.084) or between right and left eyes(1.6±0.04 vs 1.6±0.05, P=0.61). FD was nonuniformly distributed among four quadrants(P<0.001) and decreased as the distance from the fovea increased(P<0.001). A negative association was observed between FD and age(R=-0.37, P=0.006), and this relationship was observed in the posterior and mid-peripheral retina(P<0.05) but absent in far-periphery(P>0.05).CONCLUSION: Fractal geometry is non-uniformly distributed across the retina in normal eyes and decreases from the fovea to the far-periphery. Subjects with an older age tend to have a smaller FD, however, the FD in the farperiphery does not appear to be influenced by age.

Comparison of 24×20 mm^(2) swept-source OCTA and fluorescein angiography for the evaluation of lesions in diabetic retinopathy

AIM: To compare ultra-widefield(24×20 mm^(2)) sweptsource optical coherence tomography angiography(SSOCTA) and fluorescein angiography(FA) in the evaluation of diabetic retinopathy(DR) lesions. METHODS: Forty-six eyes of 23 patients with treatmentna?ve DR were included at Peking University People’s Hospital from September 1, 2021, until December 31, 2021, as well as 23 age and gender matched healthy controls. Quantitative assessments of DR lesions on FA and SS-OCTA(superficial capillary plexus, SCP, 24×20 mm^(2)) were performed.RESULTS: Area of fovea avascular zone(FAZ) was larger in DR cases than controls(0.34±0.069 mm^(2) vs 0.287±0.108 mm^(2), P=0.006). In DR eyes, the mean FAZ area was 0.34±0.069 and 0.334±0.087 mm^(2) on SS-OCTA and FA, respectively(P=0.428), while the median FAZ perimeter was 2.382(IQR, 2.201-2.59) and 2.333(IQR, 2.138-2.6) mm on SS-OCTA and FA images(P=0.733). There was no significant difference in the size of the non-perfusion area(NPA) between the images on SS-OCTA and FA(12.389, IQR 4.96-28.3 and 11.125, IQR 5-28.31 mm^(2), P=0.197). The median total microaneurysm(MA) count was 35(IQR, 19-46) and 73(IQR, 43-93) on SS-OCTA and FA(P<0.001), respectively. No significant difference in intra-retinal microvascular abnormality(IRMA) and neovascularization (NV) count was found between the two techniques. The intraclass coefficient(ICCs) of all the parameters above indicated stable repeatability.CONCLUSION: Ultra-widefield SS-OCTA represents a reliable, noninvasive, and quantitative imaging technique in the assessment of microvasculature in DR, which offers a potential substitute for FA in DR evaluation.

Quantitative analysis of retinal vasculature in normal eyes using ultra-widefield fluorescein angiography

AIM:To quantify the area and density of retinal vascularity by ultra-widefield fluorescein angiography(UWFA).METHODS:In a retrospective study,UWFA images were obtained using an ultra-widefield imaging device in 42 normal eyes of 42 patients.Central and peripheral steered images were used to define the edge of retinal vasculature by a certified grader.The length from the center of the optic disc to the edge of retinal vascularity(RVL)in each quadrant and the total retinal vascular perfusion area(RVPA)were determined by the grader using OptosAdvance software.The density of retinal vascularity(RVD)was quantified in different zones of central-steered images using Image J software.RESULTS:Among 42 healthy eyes,the values for mean RVL in each quadrant were 19.007±0.781 mm(superior),18.467±0.869 mm(inferior),17.738±0.622 mm(nasal)and 24.241±1.336 mm(temporal).The mean RVPA was 1140.117±73.825 mm^(2).The mean RVD of the total retina was 4.850%±0.638%.RVD varied significantly between different retina zones(P<0.001),and significant differences existed in the RVD values for total retinal area in patients over 50 years old compared to those under 50 years old(P=0.033).No gender difference was found.CONCLUSION:The UWFA device can be a promising tool for analyzing the overall retinal vasculature and may provide a better understanding of retinal vascular morphology in normal eyes.Aging may be related to lower RVD.

Comparison of fundus fluorescein angiography and fundus photography grading criteria for early diabetic retinopathy

AIM:To compare the assessment outcomes of the characteristics of mild to moderate non-proliferative diabetic retinopathy(NPDR) established by fundus photography and fundus fluorescein angiography(FFA).METHODS:The fundus photos and FFA results of 260 patients with diabetes mellitus were reviewed.Diabetic retinopathy(DR) severity was graded based on the international classification standard.The microaneurysms,hemorrhages,and intraretinal microvascular abnormalities(IRMA) in FFA images of patients with mild to moderate NPDR were observed.The differences between the fundus photos and the FFA results were summarized,analyzed,and compared.RESULTS:The counting of intraretinal hemorrhages identified by FFA revealed that only 9 eyes(1.9%) had more than 20 intraretinal hemorrhages in all four quadrants;15 eyes(3.1%) had more than 20 intraretinal hemorrhages in three quadrants;26 eyes(5.4%) had over 20 intraretinal hemorrhages in two quadrants;and 37 eyes(7.7%) had more than 20 intraretinal hemorrhages in only one quadrant.Furthermore,the number of IRMAs appeared ≥4 in 17 eyes,3 in 35 eyes,2 in 69 eyes,and 1 in 93 eyes.CONCLUSION:FFA has higher detection accuracy of retinal angiopathy than fundus photography.FFA grading results are helpful for timely detection and proper treatment of lesions easily missed by fundus photography.

Can Fundus Fluorescein Angiography be Performed for Diabetic Patients on Oral Metformin

Metformin is a kind of biguanide hypoglycemic agent that has been widely used in patients with diabetes mellitus. In clinical practice, whether metformin should be stopped before Fundus fluorescein angiography （FFA） remains largely unclear. Some endocrinologists suggest stop metformin before FFA. However, ophthalmologists do not always adopt this opinion in their practice. This situation may lead to disputes between physicians and patients. This article analyzed contrast-induced nephropathy（CIN） and the related contrast agent, as well as the adverse reactions of fluorescein angiography. It pointed out that the discrepancy may be caused by misunderstanding of contrast agents used in FFA. For angiography using iodine contrast agent, metformin must be stopped because of the increased possibility of CIN, while for FFA using fluorescein sodium, no CIN has been reported yet. Therefore, the authors believe FFA is safe for diabetic patients with oral metformin and it is unnecessary to stop metformin before the examination.

Changes on optical coherence tomography angiography and fluorescein angiography in eyes with neovascular age-related macular degeneration

AIM:lo evaluate the changes on optical coherence tomography angiography(OCTA) and fluorescein angiography(FA) and their correlation in neovascular agerelated macular degeneration(nAMD) before and after intravitreal aflibercept injections(IAIs).METHODS:In 43 treatment-na?ve patients with nAMD,choroidal neovascularization(CNV) in OCTA were morphologically and quantitatively analyzed before and after IAIs to determine whether they are correlated with leakage on FA or not.By combining CNV in OCTA and leakage in FA,lesions were characterized as three types:L+C+(with both CNV and leakage),L-C+(with CNV but without leakage),or L+C-lesion(with leakage outside CNV).RESULTS:Before IAI,while 27 eyes had L+C+lesion only,16 eyes had both L+C+and L-C+lesions simultaneously.Tiny capillaries and anastomosis in CNV were more developed in L+C+lesion,at 86.0% and58.1%,respectively,relative to 9.3% and 9.3% in L-C+lesions(P<0.001).After IAIs in 33 eyes,tiny capillaries and anastomosis were decreased in the lesions with cessation of leakage on FA(P<0.001 and P=0.001,respectively).In quantitative analysis,neovascularization length and numbers of junctions and endpoints were also significantly decreased.CONCLUSION:Leakage on FA is associated with CNV morphology in OCTA and remained so after IAls.Therefore,by carefully assessing the morphological and quantitative changes of CNV in OCTA before and after treatment,activity of nAMD is expected even though CNV on OCTA is not completely matched with fluorescein leakage.

Dynamic versus static ultra-widefield fluorescein angiography in eyes with diabetic retinopathy:a pilot prospective cross-sectional study

AIM:To analyze differences in ultra-widefield fluorescein angiography(UWFA)findings between dynamic and static images of eyes with diabetic retinopathy(DR).METHODS:This cross-sectional study included 28 eyes of 28 patients with DR undergoing UWFA.A series of UWFA images acquired from each patient were converted into a time-lapse video and used as a dynamic image.A single,clear,arteriovenous phase image was chosen as a static image.Non-perfusion index(NPI)and its correlation with vascular abnormalities in different zones were compared between dynamic and static UWFA imaging.RESULTS:NPI appeared to increase from the center to the far-periphery in both groups.Dynamic NPI was lower in the total retinal area(0.26 vs 0.29,P=0.009)and farperiphery(0.33 vs 0.36,adjusted P=0.042),which was contrary to the static NPI.Far-peripheral NPI was associated with intraretinal microvascular abnormality in the posterior area in both groups.CONCLUSION:Time-lapse dynamic UWFA imaging is a useful modality to differentially diagnose hypofluorescence in the most peripheral region.This modality could provide a reliable method for NPI measurement.

Fundus photography,fundus fluorescein angiography,and optical coherence tomography of healthy cynomolgus monkey,New Zealand rabbit,Sprague Dawley rat,and BALB/c mouse retinas

Background:A variety of experimental animal models are used in basic ophthalmological research to elucidate physiological mechanisms of vision and disease pathogenesis.The choice of animal model is based on the measurability of specific parameters or structures,the applicability of clinical measurement technologies,and the similarity to human eye function.Studies of eye pathology usually compare optical parameters between a healthy and altered state,so accurate baseline assessments are critical,but few reports have comprehensively examined the normal anatomical structures and physiological functions in these models.Methods:Three cynomolgus monkeys,six New Zealand rabbits,ten Sprague Dawley(SD)rats,and BALB/c mice were examined by fundus photography(FP),fundus fluorescein angiography(FFA),and optical coherence tomography(OCT).Results:Most retinal structures of cynomolgus monkey were anatomically similar to the corresponding human structures as revealed by FP,FFA,and OCT.New Zealand rabbits have large eyeballs,but they have large optic disc and myelinated retinal nerve fibers in their retinas,and the growth pattern of retinal vessels were also different to the human retinas.Unlike monkeys and rabbits,the retinal vessels of SD rats and BALB/c mice were widely distributed and clear.The OCT performance of them were similar with human beings except the macular.Conclusions:Monkey is a good model to study changes in retinal structure associated with fundus disease,rabbits are not suitable for studies on retinal vessel diseases and optic nerve diseases,and rats and mice are good models for retinal vascular diseases.These measures will help guide the choice of model and measurement technology and reduce the number of experimental animals required.

Fundus photography,fluorescein angiography,optical coherence tomography and electroretinography of preclinical animal models of ocular diseases

The eye is an immune-privileged and sensory organ in humans and animals.Anatomical,physiological,and pathobiological features share significant similarities across divergent species(1).Each compartment of the eye has a unique structure and function.The anterior and posterior compartments of the eye contain endothelium(cornea),epithelium(cornea,ciliary body,iris),muscle(ciliary body),vitreous and neuronal(retina)tissues,which make the eye suitable to evaluate efficacy and safety of tissue specific drugs(2).

Prognostic factors for acute central retinal artery occlusion treated with hyperbaric oxygen:The Hong Kong study report number five

BACKGROUND Central retinal artery occlusion(CRAO)is a potentially blinding disease,and hyperbaric oxygen therapy(HBOT)is becoming increasingly popular with the support of scientific evidence.Despite the presence of various acute management measures,there is no clear evidence on the gold standard treatment for CRAO.AIM To identify factors and imaging parameters associated with good visual outcome,which guide ophthalmologists in the triage of CRAO patients for HBOT.METHODS Patients who suffered from CRAO and had a symptom onset≤6 h were recruited for a course of HBOT in a tertiary hospital after failing bedside treatment.Patient demographics,onset time,CRAO eye parameters,and past medical history were prospectively collected.Visual outcomes after HBOT were also analyzed.RESULTS A total of 26 patients were included;the female-to-male ratio was 1:1.6,and the mean age was 67.5 years±13.3 years(range 44–89 years).The mean duration of follow-up and mean visual acuity(VA)improvement were 10.0 mo±5.3 mo and 0.48 logarithm of minimal angle of resolution(logMAR)±0.57 logMAR(approx-imately 9 letters in ETDRS)(P=0.0001,Z=-3.67),respectively.The 1 mm zone of central macular thickness(CMT)on optical coherence tomography was not associated with VA changes(P=0.119);however,the 1-to-3 mm circular rim of CMT was fairly associated(P=0.02,Spearman's coefficient=0.45).Complete retinal perfusion time during fundus fluorescein angiography(FFA)was mode-rately associated(P=0.01,Spearman's coefficient=0.58)with visual outcome.

Foveal avascular zone area and parafoveal vessel density measurements in different stages of diabetic retinopathy by optical coherence tomography angiography

AIM：To investigate foveal avascular zone（FAZ）and parafoveal vessel densities（PRVD）by means of optical coherence tomography angiography（OCTA）in diabetic patients with or without diabetic retinopathy（DR）and to assess the reproducibility of FAZ and PRVD measurements.METHODS：Sixty diabetic patients（60 eyes）with different stage of DR（graded according to the International Clinical Severity Scale for DR）and 20 healthy subjects underwent FAZ area and PRVD measurements using OCTA by two experienced examiners.FAZ area in all patients was also assessed using fluorescein angiography（FA）.RESULTS：In subject with proliferative DR and with moderate-severe non proliferative DR,FAZ area was significantly increased compared to healthy controls（P=0.025 and P=0.050 respectively measured with OCTA and P=0.025 and P=0.048 respectively measured with FA）.OCTA showed significantly less inter-observer variability compared to FA.Concordance correlation coefficient（CCC）for FAZ area measurements was 0.829（95%CI：0.736-0.891）P〈0.001 with FA and 1.000（95%CI：0.999-1.000）P〈0.001with OCTA.CCC was 0.834（95%CI：0.746-0.893）P〈0.001and 0.890（95%CI：0.828-0.930）P〈0.001 for parafoveal superficial and deep vessel density measurements,respectively.CONCLUSION：OCTA shows progressive increase of FAZ area and reduction of PRVD in both superficial and deep plexus at increasing DR severity.FAZ area and PRVD measurements using OCTA are highly reproducible.

Peripheral arterial filling time and peripheral retina fluorescence features in ultra-widefield angiography

AIM:To evaluate the peripheral arterial filling time(PAFT)and venous filling time(VFT)in eyes without known diseases that may influence filling process using ultra-widefield(UWF)fluorescein angiography(FA),and to review the peripheral retina fluorescence features.METHODS:A total of 30 eyes of 30 patients were retrospectively reviewed in this observational study.UWFFA was performed using Optos 200Tx.PAFT and VFT was recorded.The interval between the arterial or venous filling completion and the previous photo was documented.The appearance of the far peripheral retina was described as either granular background fluorescence or mottled fluorescent band or vascular leakage.Terminal vascular patterns was described as loop pattern or branching pattern.Microvascular abnormalities such as arteriovenous shunting,vessels crossing the horizontal raphe,right angle vessels,terminal networks,capillary nonperfusion,drusen or microaneurysms were evaluated.RESULTS:The normal limits of PAFT was 3.397-8.984s and 4.399-11.753s for VFT.The appearance of the far peripheral retina,defined as granular background(63%),mottled fluorescence(20%),or vascular leakage(17%),was symmetrical between both eyes.Capillary nonperfusion(23%)and microaneurysms(40%)were more frequently found in eyes with loop pattern than in eyes with branching pattern.Other peripheral signs such as right-angle vessels(73%),and terminal networks(80%)were commonly seen on UWF-FA in the normal peripheral retina.CONCLUSION:The main courses of retinal artery and vein filling time are overlapping with each other on UWF-FA.Notably,the arterial filling process is completed in the arteriovenous phase rather than the traditionally named arterial phase.There are various manifestations in the peripheral retina of normal eyes.

Application of non-mydriatic fundus photography-assisted telemedicine in diabetic retinopathy screening

BACKGROUND Early screening and accurate staging of diabetic retinopathy(DR)can reduce blindness risk in type 2 diabetes patients.DR’s complex pathogenesis involves many factors,making ophthalmologist screening alone insufficient for prevention and treatment.Often,endocrinologists are the first to see diabetic patients and thus should screen for retinopathy for early intervention.AIM To explore the efficacy of non-mydriatic fundus photography(NMFP)-enhanced telemedicine in assessing DR and its various stages.METHODS This retrospective study incorporated findings from an analysis of 93 diabetic patients,examining both NMFP-assisted telemedicine and fundus fluorescein angiography(FFA).It focused on assessing the concordance in DR detection between these two methodologies.Additionally,receiver operating characteristic(ROC)curves were generated to determine the optimal sensitivity and specificity of NMFP-assisted telemedicine,using FFA outcomes as the standard benchmark.RESULTS In the context of DR diagnosis and staging,the kappa coefficients for NMFPassisted telemedicine and FFA were recorded at 0.775 and 0.689 respectively,indicating substantial intermethod agreement.Moreover,the NMFP-assisted telemedicine’s predictive accuracy for positive FFA outcomes,as denoted by the area under the ROC curve,was remarkably high at 0.955,within a confidence interval of 0.914 to 0.995 and a statistically significant P-value of less than 0.001.This predictive model exhibited a specificity of 100%,a sensitivity of 90.9%,and a Youden index of 0.909.CONCLUSION NMFP-assisted telemedicine represents a pragmatic,objective,and precise modality for fundus examination,particularly applicable in the context of endocrinology inpatient care and primary healthcare settings for diabetic patients.Its implementation in these scenarios is of paramount significance,enhancing the clinical accuracy in the diagnosis and therapeutic management of DR.This methodology not only streamlines patient evaluation but also contributes substantially to the optimization of clinical outcomes in DR management.

Spectral Domain Optical Coherence Tomography of Vogt-Koyanagi-Harada Disease: Novel Findings and New Insights into the Pathogenesis

Objective To provide novel spectral domain optical coherence tomography (SD OCT) findings of Vogt-Koyanagi-Harada (VKH) disease as well as new insights into the pathogenesis of this disease. Methods Detailed SD OCT and fluorescein angiography (FA) findings of 18 consecutive VKH patients (11 women and 7 men) from December 2007 to April 2009 who were in acute uveitic stage at presentation were reviewed. All the patients had been followed up for at least 6 months with reevaluation(s) of SD OCT performed in 10 patients. Results Intraretinal cysts were found to be located in various layers of the outer retina. In addition to the photoreceptor layer, they could also be found between the outer plexiform layer and the outer nuclear layer, or spanning the external limiting membrane. On FA, intraretinal cysts could be hypofluorescent, normofluorescent, or hyperfluorescent. Some intraretinal cysts had a characteristic FA pattern, in which a small round hypofluorescent area was surrounded by a ring of hyperfluorescence (donut-shaped dye pooling). Subretinal fibrinoid deposit appeared in acute uveitic stage in two severe VKH patients and seemed to develop from subretinal exudates and evolved into typical subretinal fibrosis. Gradual transfiguration/migration and progressive proliferation/pigmentation of the subretinal fibrinoid deposit/subretinal fibrosis was observed in one patient. Conclusions Intraretinal cysts could form in various layers of the outer retina and may result from extension of choroidal inflammation. Subretinal fibrosis may develop from subretinal exudates in VKH patients and may cause substantial visual impairment.

Comparison of autofluorescence and optical coherence tomography findings in acute and chronic central serous chorioretinopathy

AIM:To discuss and compare the fundus autofluorescence(FAF)and optical coherence tomography(OCT)in acute or chronic central serous chorioretinopathy(CSCR).METHODS:Medical records of 100 cases of CSCR were reviewed.Acute and chronic cases were evaluated according to the duration of decreased visual acuity,serous retinal detachment(RD)and focal leakage on fluorescein angiography(FA).Chi-square test was used for statistical analysis.RESULTS:Forty cases had acute and 60 cases had chronic CSCR.FAF showed focal hypo-autofluorescence in 34(85%)and iso-autofluorescence in 6(15%)of acute cases and hypo-autofluorescence in 51(85%),hyperautofluorescence in 6(10%)and iso-autofluorescence in3(5%)of chronic cases.OCT showed serous RD with distinct borders correlated with FAF findings(hypoautofluorescence)in all acute CSCR cases.In chronic CSCR group,OCT showed serous RD with indistinct borders correlated with FAF findings.The differences between the OCT and FAF findings of the two groups were significant(P=0.000).CONCLUSION:OCT and FAF findings can support the clinical observations in differential diagnosis of acute and chronic CSCR and help clinicians to evaluate retinal pigment epithelium,outer segments of photoreceptors and the components of serous RD.

Protective effects of umbilical cord mesenchymal stem cell exosomes in a diabetic rat model through live retinal imaging

AIM:To assess the protective effect of human umbilical cord mesenchymal stem cell exosomes(hucMSC-Exs)in a diabetic rat model by using a variety of retinal bioassays.METHODS:hucMSCs were subjected to differential ultracentrifugation for the collection of exosomes,and transmission electron microscopy(TEM),nanoparticle tracking analysis(NTA)using a NanoSight analysis system and Western blotting(WB)were used to analyze the expression of surface marker proteins such as CD63,CD9 and Calnexin.Streptozotocin(STZ)was injected into the intraperitoneal cavity to establish a diabetic model.Rats were divided into a normal group,diabetic group and hucMSC-Ex group.Fundus fluorescein angiography(FFA),optical coherence tomography(OCT)and other live imaging methods were used to observe the fundus of the rats.Finally,the eyeballs of rats from each group were collected for hematoxylin-eosin(HE)staining to further analyze the retinal structure.RESULTS:Through TEM,NTA and WB,we successfully isolated hucMSC-Exs.Subsequent FFA and OCT confirmed that hucMSC-Exs effectively prevented early retinal vascular damage and thickening of the retina.Finally,HE staining of rat retinal sections revealed that exosomes effectively alleviated retinal structure disruption caused by diabetes.CONCLUSION:hucMSC-Exs have a protective effect on the retina in diabetic rat through FFA,OCT and HE staining.

Retinal circulation and its role in macular disorders in patients without systemic disease

AIM: To determine whether retinal circulatory changes play a role in the pathogenesis of macular disorders in patients who are otherwise healthy. METHODS: Patients with macular disorders that required angiographic imaging were included in this prospective case series. After a complete ocular exam,fluorescein angiography was performed using a standardized technique on the HRA-II(Heidelberg Engineering, Heidelberg, Germany) with special focus on the posterior pole. Only patients with good quality images were included in the analysis. Circulatory parameters recorded included the arm-choroid time,choroid-retinal artery, and finally the retinal artery-vein time. Zonal asymmetry(between the upper and lower zones divided by a line passing through the centre of the fovea) in transit times, if any was also noted. Appropriate statistical analysis was done. Circulation times were compared with age matched historical controls. Changes in retinal dye transit times relative to historical age matched controls, if any, were noted and compared between various disorders.RESULTS: A total of 156 eyes of 156 patients(120 males)were included in the study. Mean age: 49.14 ±14.93 y.Macular disorders studied were age related degeneration,polypoidal vasculopathy, central serous chorioretinopathy(CSCR) and parafoveal telangiectasia. Delayed circulation time was noted in CSCR patients only.CONCLUSION: CSCR patients appear to have delayed arterial filling, retinal circulatory disturbances do not seem to contribute to the pathogenesis of other macular disorders.

Clinical features of retinal amyloid angiopathy with transthyretin Gly83Arg variant

AIM:To report on the clinical features of patients with retinal amyloid angiopathy(RAA)who were identified to be caused by the transthyretin(TTR)Gly83Arg variant.METHODS:Case series of five patients diagnosed with RAA was collected at Affiliated Hospital of Zunyi Medical University from January 2010 to December 2021.The clinical features,therapeutic strategies,and prognoses of all patients were reviewed.RESULTS:Five patients with a mean age of 52.00±7.23y were diagnosed as RAA.These patients were previously diagnosed with hereditary transthyretin amyloidosis caused by the TTR Gly83Arg variant.Vitreous opacity was found in all 10 eyes,and 7 eyes developed RAA 2 to 20y after the onset of hereditary transthyretin amyloidosis.The clinical manifestations were recurrent vitreous hemorrhage in 2 eyes(29%),neovascular glaucoma in 2 eyes(29%),and iris neovascularization in 1 eye(14%).Microangioma lesions were found in all affected eyes that underwent fundus fluorescein angiography(FFA)in this group of cases,and the incidence of the retinal non-perfusion area was 67%.Although no cases of retinal neovascularization were found,the prognosis of visual acuity was not ideal.CONCLUSION:This is the first report of RAA in patients with the TTR Gly83Arg variant.Complications such as RAA and glaucoma will seriously affect the visual prognosis of patients.Thereafter,regular ophthalmic follow-up of patients with hereditary transthyretin amyloidosis is essential.And FFA after vitrectomy is very important,which can help ophthalmologists detect RAA earlier and treat it in time.